Prenatal physical, language, and cognitive developmental milestones are as follows:

Physical – in the first month the embryo has the most rapid prenatal changes to prepare for the development of all body structures and internal organs (Berk, 2013).

The embryonic disk forms three layers of cells: (1) the ectoderm, which will become the nervous system and skin; (2) the mesoderm, from which will develop the muscles, skeleton, circulatory system, and other internal organs; and (3) the endoderm, which will become the digestive system, lungs, urinary tract, and glands.  These three layers give rise to all parts of the body (Berk, 2013).

Language – in the second month, production of neurons (nerve cells that store and transmit information) the neurons begin traveling along tiny threads to their permanent locations, where they will form the major parts of the brain.  It responds to touch, particularly in the mouth area and on the soles of the feet.  And it can move, although its tiny flutters are still too light to be felt by the mother (Berk, 2013)

Cognitive – in the third month, the organs, muscles, and nervous system start to become organized and connected.  When the brain signals, the fetus kicks, bends its arms, forms a fist, curls its toes, turns its head, opens its mouth, and even sucks its thumb, stretches, and yawns.